Example usage for org.bouncycastle.jce.spec ECNamedCurveSpec getName

Introduction

In this page you can find the example usage for org.bouncycastle.jce.spec ECNamedCurveSpec getName.

Prototype

public String getName() 

Source Link

Document

return the name of the curve the EC domain parameters belong to.

Usage

From source file:me.grapebaba.hyperledger.fabric.Crypto.java

License:Apache License

public ByteString eciesDecrypt(PrivateKey recipientPrivateKey, ByteString cipherText) {
    BCECPrivateKey bcecPrivateKey = (BCECPrivateKey) recipientPrivateKey;
    ECNamedCurveSpec ecNamedCurveSpec = (ECNamedCurveSpec) bcecPrivateKey.getParams();
    int level = SecurityLevel.from(ecNamedCurveSpec.getName()).size();

    //cipherText = ephemeralPubKeyBytes + encryptedTokBytes + macBytes
    //ephemeralPubKeyBytes = first ((384+7)/8)*2 + 1 bytes = first 97 bytes
    //hmac is sha3_384 = 48 bytes or sha3_256 = 32 bytes
    int ephemeralPubKeyLength = ((level + 7) / 8) * 2 + 1;
    int hmacLength = level >> 3;
    int cipherTextLength = cipherText.size();

    if (cipherTextLength <= ephemeralPubKeyLength + hmacLength)
        throw new RuntimeException(String.format("Illegal cipherText length: %d must be > %d", cipherTextLength,
                ephemeralPubKeyLength + hmacLength));

    ByteString ephemeralPubKey = cipherText.substring(0, ephemeralPubKeyLength);
    ByteString encryptedContent = cipherText.substring(ephemeralPubKeyLength, cipherTextLength - hmacLength);
    ByteString hmac = cipherText.substring(cipherTextLength - hmacLength);

    ECPrivateKeyParameters ecdhPrivateKeyParameters;
    try {//from   w  ww.java 2 s .  co m
        ecdhPrivateKeyParameters = (ECPrivateKeyParameters) (PrivateKeyFactory
                .createKey(bcecPrivateKey.getEncoded()));
    } catch (IOException e) {
        logger.error("ECIES decrypt load private key exception", e);
        throw new RuntimeException(e);
    }
    ECDomainParameters ecDomainParameters = ecdhPrivateKeyParameters.getParameters();
    ECCurve ecCurve = ecDomainParameters.getCurve();
    ECPublicKeyParameters ecPublicKeyParameters = new ECPublicKeyParameters(
            ecCurve.decodePoint(ephemeralPubKey.toByteArray()), ecDomainParameters);
    BasicAgreement agree = new ECDHBasicAgreement();
    agree.init(ecdhPrivateKeyParameters);
    byte[] keyAgreement = agree.calculateAgreement(ecPublicKeyParameters).toByteArray();

    HKDFParameters hkdfParameters = new HKDFParameters(keyAgreement, null, null);
    HKDFBytesGenerator hkdfBytesGenerator = new HKDFBytesGenerator(digest);
    hkdfBytesGenerator.init(hkdfParameters);
    byte[] hkdfOutputBytes = new byte[AESKEY_LENGTH + HMACKEY_LENGTH];
    hkdfBytesGenerator.generateBytes(hkdfOutputBytes, 0, AESKEY_LENGTH + HMACKEY_LENGTH);
    ByteString hkdfOutput = ByteString.copyFrom(hkdfOutputBytes);
    ByteString aesKey = hkdfOutput.substring(0, AESKEY_LENGTH);
    ByteString hmacKey = hkdfOutput.substring(AESKEY_LENGTH, AESKEY_LENGTH + HMACKEY_LENGTH);
    HMac hMac = new HMac(digest);
    hMac.init(new KeyParameter(hmacKey.toByteArray()));
    hMac.update(encryptedContent.toByteArray(), 0, encryptedContent.size());
    byte[] recoveredHmac = new byte[hMac.getMacSize()];
    hMac.doFinal(recoveredHmac, 0);
    if (!MessageDigest.isEqual(hmac.toByteArray(), recoveredHmac)) {
        throw new RuntimeException("HMAC verify failed");
    }

    CFBBlockCipher aesCipher = new CFBBlockCipher(new AESEngine(), BLOCK_BIT_SIZE);
    ByteString iv = encryptedContent.substring(0, IV_LENGTH);
    CipherParameters ivAndKey = new ParametersWithIV(new KeyParameter(aesKey.toByteArray()), iv.toByteArray());
    aesCipher.init(false, ivAndKey);
    byte[] decryptedBytes = new byte[500];
    aesCipher.decryptBlock(encryptedContent.substring(IV_LENGTH).toByteArray(), 0, decryptedBytes, 0);
    return ByteString.copyFrom(decryptedBytes);
}

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From source file:net.sf.keystore_explorer.crypto.ecc.EccUtil.java

License:Open Source License

/**
 * Determines the name of the domain parameters that were used for generating the key.
 *
 * @param key An EC key/*from   ww w. j av  a2 s. c o  m*/
 * @return The name of the domain parameters that were used for the EC key,
 *         or an empty string if curve is unknown.
 */
public static String getNamedCurve(Key key) {

    if (!(key instanceof ECKey)) {
        throw new InvalidParameterException("Not a EC private key.");
    }

    ECKey ecKey = (ECKey) key;
    ECParameterSpec params = ecKey.getParams();
    if (!(params instanceof ECNamedCurveSpec)) {
        return "";
    }

    ECNamedCurveSpec ecPrivateKeySpec = (ECNamedCurveSpec) params;
    String namedCurve = ecPrivateKeySpec.getName();
    return namedCurve;
}

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From source file:org.jmrtd.Util.java

License:Open Source License

/**
 * Gets the curve name if known (or null).
 *
 * @param params an specification of the curve
 *
 * @return the name// www . j  a v  a2 s. c  om
 */
public static String getCurveName(ECParameterSpec params) {
    org.bouncycastle.jce.spec.ECNamedCurveSpec namedECParams = toNamedCurveSpec(params);
    if (namedECParams == null) {
        return null;
    }
    return namedECParams.getName();
}

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